GTR choking & surging for first 3 minutes

[Penfold]

Yeh, I just got my GTR back from my mechanice. Just upgraded CAT & changed spark plugs & made a CAI & partition for my pods & decided to back timing back a little. Unfortunately when I first drive the car round for the first 3 minutes or so it runs pretty rough - surging & choking with constant appliaction of throttle. Whereas before it had really smooth power delivery & well after the first initial driving it runs really well. Any ideas?

Its only when you first switch the car on of a morning or its been left sitting for about 10 hours - it doenst do it if it has been sitting for a couple of hours.

Oh, dropped the timeing back a little because I had to run 96 octane for a couple of months but now got BP Ultimate so i will advance it again.

I'm thinking that backing off the timing combined with the cold air intake is causing the problems (engine hasnt had a chance to heat up yet).

Any ideas,

Geoff

[Mase]

hey mate, my rb20det does the same, i have changed afm, plugs, o2 sensor and the injectors have been cleaned and flow tested and still does it. Just something for you to go on. Cheers

[Penfold]

Yeh its a little strange - its only when the engine is cold. The psi definitely rises up (a little shakily) but theres a definite absense of power (my boost guage could read 0.5 bar & its only very slow & iffy power). But after it warms up (less than 5 minutes) it goes like a champion again - at 0.5 bar its definietly pushes you back in your seat.

I guess maybes its worth advancing the time & an ECU reset????

Any clues before I take it in?

[kaz]

i had a similar prob too and thought it might be the 02 sensor, but turned out it was due to a loose earth wire near the CAT.

[Mase]

I've done a few battery resets with no solution. CAT. Crank angle ??? please explain kaz

[kaz]

not sure if it will be the same for ur car, but there was a flat braided earth wire joining the catalytic converter to the car body(not the temp sensor wire), which had come loose on mine. Once this was connected up properly, the cold surging/choking prob went away.

Not exactly sure why, but I was told that the earth wire affected the function of the o2 sensor.

[rb25]

dont you hate it when you drop your car off to a mech., pick it up and something else is f**ked. i hate ametuer/dodgy mechanics, just do the work yourself next time or find someone who is reputable.

-rb25

[RB20LagWagon]

Id suggest it is the timing. Put it back to factory setting

[Blitz]

Penfold: I had a similar drama with my GTR when I first got it. when the car was cold it was coughing and spluttering. If its only doing it when cold then check for a gasket leak. I had a leak behind the inlet manifold though as the car heated up, the gasket expanded and the leak went away. I also had a faulty O2 sensor which was actually the root of the problem, but the gasket issue didnt help. Get both checked.

Hope this helps